20190106_b.cpp

#include <bits/stdc++.h>
using namespace std;
using ull = unsigned long long;
using ll = long long;
using vi = vector<int>;
using vl = vector<long>;
using vll = vector<long long>;
using vvi = vector<vi>;
using vvl = vector<vl>;
using vvll = vector<vll>;
using vs = vector<string>;
using pii = pair<int, int>;
#define REP(i,n) for(int i=0; i<(n); i++)
#define REP2(i,x,n) for(int i=x; i<(n); i++)
#define ALL(n) begin(n),end(n)
#define PRINT(n) cout << n << endl;
struct cww{cww(){ios::sync_with_stdio(false);cin.tie(0);}}star;
const long long INF = numeric_limits<long long>::max();
int main()
{
    int n, k;
    cin >> n >> k;
    vll h(n);
    REP(i, n) cin >> h[i];

    // dp配列の定義
    ll dp[n];
    // dp配列の初期化
    REP(i, n) dp[i] = INF;
    // dp配列の初期条件
    dp[0] = 0;
    REP2(i, 1, n){
        if(i > 1){
            REP2(j, 1, k+1) dp[i] = min(dp[i], dp[i-j]+abs(h[i]-h[i-j]));
        }else{
            dp[i] = dp[i-1] + abs(h[i]-h[i-1]);
        }
    }
    PRINT(dp[n-1])
    return 0;
}